Research will be conducted on the effect of aging on the abilities of concern in preparation for a rapid response. Following are the particular investigations. The utilization of an information-reducing cue: A choice reaction will be reduced from four to two alternatives by a cue which occurs 0.5 sec before the signal for response. It has already been found - contrary to conclusions in the literature - that older people can use a probability-increasing cue. The time course of attaining preparation: For both of the foregoing manipulations a range of values of the cue-signal interval will be employed. The maintaining of preparation for a choice response: Following the technique employed in the previous year for simple reactions, a constant momentary-probability signal will be employed. The utilizing of an information reducing cue in serial performance. Adaptive pacing will be used to find the highest rate of error-free performance with and without a cue which reduces alternatives from four to two. In all of the studies, top performers across the adult age span will be compared and sufficient practice will be given to remove temporary effects.